The present invention relates to a light fixture that has a straight molded dual pin hinge design. The body of the fixture is cast with a molded-in hinge component that has a split trough with a ball rib in one trough. The lens frame is cast with a molded-in hinge component that has dual pins extending therefrom and a ball groove at the base of one of the pins. The dual pins slide into the trough with the ball rib surrounding the ball groove and acting as a self-centering device that allows for ample room between the mounting member and lens frame for pivoting movement there between.
Access to the interior of a light fixture is generally necessary to change the light source or alter the direction the light projects by adjusting a reflector assembly. Many light fixtures allow interior access through a pivoting lens frame attached to a relatively stationary mounting member. The lens frame is usually attached using a hinge, which must enable the lens frame to open and allow full, unrestricted access to the interior of the light fixture.
Conventional hinge designs for luminaires commonly use a cantilevered single pin design. The pin single is usually relatively long making the hinge more likely to fail due to significant shear and compression forces from the weight of the corresponding hinged device. In addition, the hinge parts are individually diecast and attached to the lens frame or mounting member through various methods, such as screws or glue. This design creates a hinge that protrudes from the mounting member and frame. If the hinge is made too compact to avoid protrusions, the hinge will not have ample clearance and may bind.
When multiple hinges are used and spaced substantial distances from each other, relatively large tolerances must be built into the diecast mold. These tolerances require that a hinge be moved away from the hinged element to allow enough clearance for the pivoting of the hinged parts. Many hinges are designed to be as compact as possible for a smooth appearance, but they still must allow for clearance tolerances that must be built into the mold, limiting compactness.
If a hinge component is molded-in with its corresponding hinged element, cams, lifters, or secondary operations are generally necessary. Cams and lifters enable a cast to be removed from a mold even if the mold has undercuts. Designing a diecast hinge that can be straight molded without using any of these procedures is difficult. Use of cams and lifters to remove a mold from its cast only adds time and expense to a molding procedure. The same is true for secondary operations. Secondary operations are added steps after a diecast is removed from a mold, such as drilling a hole for a screw. Therefore designing a hinge assembly that can be manufactured without using cams, lifters, or secondary operations and that is simple to use and cost effective to make is important.
Accordingly, an object of the present invention is to provide light fixture hinge assemblies for the mounting member and lens frame that can be straight molded without cams, lifters or secondary operations, thereby reducing the manufacturing time and expense.
Another object of the present invention is to provide a light fixture hinge that is self-centering with a dual pin and split trough configuration, providing ample clearance between the dual pin component and the split trough component while maintaining a smooth fit and finish.
Still another object of the present invention is to provide a light fixture hinge that is molded-in enabling its trough and pins to be located close to the edges of the hinged parts.
Yet another object of this invention is to provide a light fixture hinge having a dual pin and split trough configuration that is diecast and molded simultaneously with the hinged part, producing a strong, compact, and unobtrusive hinge that is aesthetically pleasing.
The foregoing objects are basically attained by providing a hinge assembly for a light fixture having two pieces. The first piece has a unitary hinge element having first and second sections with a ball rib located in the first section. The second piece has a unitary hinge element, which slides into the first unitary hinge element, and has a first and second pin, the first pin having an annular ball groove.
By forming the light fixture hinge assembly in this manner, the resultant design has exceptional strength. The straight molded dual pin design locates the trough and the hinge pins close to the edges of mounting member and the body. This configuration also provides a compact, unobtrusive design with minimum protrusion from the pin assembly and the trough assembly.
Other objects, advantages and salient features of the invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawings, discloses a preferred embodiment of the invention.